Intraoperative Near-Infrared Fluorescence Guided Surgery Using Indocyanine Green (ICG) for the Resection of Sarcomas May Reduce the Positive Margin Rate: An Extended Case Series

SIMPLE SUMMARY: Sarcomas are rare cancers that can arise all over the body, with many occurring in younger people. Treatment is usually based around surgery to remove the tumour. It is crucial to remove all of the tumour to minimise the chance of the tumour coming back. Currently, surgeons review scans of the tumour and plan the operation beforehand, but it can be difficult to relate the scans to what the surgeon sees during the operation. Currently, there are no established technologies to help them identify the tumour during the operation. Here we have given patients a harmless dye (indocyanine green) prior to the operation, which makes the tumour glow on a screen when seen by a camera during the operation, helping the surgeon to identify and remove the tumour. This resulted in the surgeon being able to remove all of the tumour more often, reducing the chances of it coming back. ABSTRACT: Background: Sarcomas are rare, aggressive cancers which can occur in any region of the body. Surgery is usually the cornerstone of curative treatment, with negative surgical margins associated with decreased local recurrence and improved overall survival. Indocyanine green (ICG) is a fluorescent dye which accumulates in sarcoma tissue and can be imaged intraoperatively using handheld near-infrared (NIR) cameras, theoretically helping guide the surgeon’s resection margins. Methods: Patients operated on between 20 February 2019 and 20 October 2021 for intermediate to high grade sarcomas at our centres received either conventional surgery, or were administered ICG pre-operatively followed by intra-operative NIR fluorescence guidance during the procedure. Differences between the unexpected positive margin rates were compared. Results: 115 suitable patients were identified, of which 39 received ICG + NIR fluorescence guided surgery, and 76 received conventional surgery. Of the patients given ICG, 37/39 tumours fluoresced, and surgeons felt the procedure was guided by the intra-operative images in 11 cases. Patients receiving ICG had a lower unexpected positive margin rate (5.1% vs. 25.0%, p = 0.01). Conclusions: The use of NIR fluorescence cameras in combination with ICG may reduce the unexpected positive margin rate for high grade sarcomas. A prospective, multi-centre randomised control trial is now needed to validate these results.